This reads a single byte from a device, without specifying a device register. Some devices are so simple that this interface is enough; for others, it is a shorthand if you want to read the same register as in the previous SMBus command

Writes a maximum of 32 bytes in a single block to the i2c device. The supplied $values should be an array ref containing the bytes to be written.

The register address should be one that is at the beginning of a contiguous block of registers of equal length to the array of values passed. Not adhering to this will almost certainly result in unexpected behaviour in the device.

Read $numBytes form the given register address, data is returned as array

The register address is often 0x00 or the value your device expects

common usage with micro controllers that receive and send large amounts of data: they almost always needs a 'command' to be written to them then they send a response: e.g: 1) send 'command' with writeBlockData, or writeByteData, for example 'get last telegram' 2) read 'response' with readBlockData of size $numBytes, controller is sending the last telegram

Writing your own chipset driver for your own i2c devices is quiet simple. You just need to know the i2c address of your device and the registers that you need to read or write. Follow the manual at Device::SMBus::Manual.

I wrote this library for my Quadrotor project for controlling PWM Wave Generators ( ESC or DC motor controller ), Accelerometer, Gyroscope, Magnetometer, Altimeter, Temperature Sensor etc. However this module can also be used by anyone who wishes to read or control motherboard devices on I2C like laptop battery system, temperature or voltage sensors, fan controllers, lid switches, clock chips. Some PCI add in cards may connect to a SMBus segment.

The SMBus was defined by Intel in 1995. It carries clock, data, and instructions and is based on Philips' I2C serial bus protocol. Its clock frequency range is 10 kHz to 100 kHz. (PMBus extends this to 400 kHz.) Its voltage levels and timings are more strictly defined than those of I2C, but devices belonging to the two systems are often successfully mixed on the same bus. SMBus is used as an interconnect in several platform management standards including: ASF, DASH, IPMI.